1. Field of the Invention
The present invention relates to a resin containing an antibacterial agent, and specifically relates to a resin containing photocatalytic apatite.
2. Description of the Related Art
Mobile devices such as portable information devices, cellular phones, and the like come into contact with human hands, and thus dust and the like stick to these devices through grease of hands, tobacco tar, and the like. The grease of hands, tobacco tart, and dust allow various bacteria to proliferate. As a result, the appearances and cleanliness of mobile devices are impaired. On the other hand, interest in antibiotic properties is heightened, and thus an antibacterial measure is strongly required for casings, operational keys, and the like of potable information devices, cellular phones, etc. In general, titanium oxide (TiO2) is used as an antibacterial agent. For example, a resin is mixed with titanium oxide to prepare a coating resin containing titanium oxide, and the coating resin is laminated on a casing resin through a protective film. Also, the surface of a key is coated with a coating resin containing titanium oxide. The key containing titanium oxide is described in Patent Documents 1 and 2:
Patent Document 1: Japanese Unexamined Patent Application Publication No. 9-102238
Patent Document 2: Japanese Unexamined Patent Application Publication No. 11-195345
Furthermore, microcapsules of titanium oxide are mixed in a resin to prepare a coating resin. A key using this coating resin is disclosed in Patent Document 3:
Patent Document 3: Japanese Unexamined Patent Application Publication No. 9-190254
However, in any one of Patent Documents 1 to 3, an antibacterial coating layer must be formed on a resin molding, and thus the number of the production steps is increased to increase cost. Furthermore, in Patent Documents 1 to 3, a coating film containing an antibacterial agent is scraped off little by little at each time of keying, and finally the film is completely removed to lose the antibacterial function.
A conceivable measure against this is to directly mix an antibacterial agent with a resin. However, this method cause deterioration in the resin used as a raw material due to titanium oxide used as the antibacterial agent. In other words, so-called chalking occurs, in which a resin surface is gradually floured with titanium oxide. It has recently been thought that like titanium oxide, photocatalytic apatite studied as an antibacterial agent alternative to titanium oxide also produces chalking. Therefore, as disclosed in Patent Document 4, even when photocatalytic apatite is used as an antibacterial agent, a coating resin is prepared and coated to form an antibacterial coating layer on a surface of a resin molding.
Patent Document 4: Japanese Patent Application No. 2002-146110